APPLICANT'S ABSTRACT: Coronary atherosclerosis is the leading cause of death in the United States in both women and men. Several epidemiologic studies have found decreased mortality from coronary disease among people who use alcohol moderately. It is known that many individuals who consume alcohol even in small amounts have increased levels of total plasma high density lipoproteins (HDL). This effect may mediate at least a portion of the effect of alcohol on cardiovascular mortality because it is well known that higher levels of HDL are associated with lower risk. This project is directed at elucidation of the effects of moderate alcohol consumption on HDL and its antiatherogenic functions at the molecular level. Previous attempts to understand these effects have been impeded by the fact that the method heretofore employed to separate HDL species, i.e. ultracentrifugation, has been found to disrupt their architecture such that they cannot be effectively studied. This project will exploit major advances in immunosorption techniques that permit measurement of the effects of alcohol on the native molecular species of HDL, avoiding ultracentrifugation, and will assess the effects on two antiatherogenic functions of HDL, the inhibition of oxidation of low density lipoproteins, and the retrieval of cholesterol from cells. The results of these studies will be important in establishing public health policy with respect to the relative benefits and risks of moderate alcohol consumption.